The Resideo M847D-VENT Damper Actuator is intended to control fresh air dampers in HVAC systems with accuracy and dependability. This spring return actuator, which runs on a 24V power source, guarantees that the damper closes when not in use, thereby increasing energy economy. It has a 30-second motor timing for quick and precise damper placement and a 2-position control signal for si... https://www.partshnc.com/m847d-vent-resideo-24v-sr-closed-freshairdampact